If it really is the best then it's worth paying for, but from the rumours nothing is new on this upcoming model to justify a price increase other than the Touch ID built into the display. However this feature alone doesn't justify a £1000+ pricing. OLED screens, wireless charging, curved glass etc have all been around on other phones for years. They're no longer cutting edge tech and prices for them would be lower not higher. Apple doesnt create any of this tech from scratch they purchase in bulk at the lowest price then mash it altogether into the iPhone, which means there is no justification for such price increases.
iPhones haven't been the best for the last few years, I continue to buy them for iOS because it works seemlessly with my Mac and the majority of my family use them and we can FaceTime. iPhone 6, 6S and 7 are identical in design with a few minor improvements in the standard CPU, GPU and camera areas. They've been stale for years other than yearly price increases.